Commit Graph

118 Commits

Author SHA1 Message Date
David S. Miller
b3f7e3f23a Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/net 2020-01-19 22:10:04 +01:00
Vladimir Oltean
27afe0d34e net: dsa: sja1105: Don't error out on disabled ports with no phy-mode
The sja1105_parse_ports_node function was tested only on device trees
where all ports were enabled. Fix this check so that the driver
continues to probe only with the ports where status is not "disabled",
as expected.

Fixes: 8aa9ebccae ("net: dsa: Introduce driver for NXP SJA1105 5-port L2 switch")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-17 13:22:12 +01:00
Florian Fainelli
4d776482ec net: dsa: Get information about stacked DSA protocol
It is possible to stack multiple DSA switches in a way that they are not
part of the tree (disjoint) but the DSA master of a switch is a DSA
slave of another. When that happens switch drivers may have to know this
is the case so as to determine whether their tagging protocol has a
remove chance of working.

This is useful for specific switch drivers such as b53 where devices
have been known to be stacked in the wild without the Broadcom tag
protocol supporting that feature. This allows b53 to continue supporting
those devices by forcing the disabling of Broadcom tags on the outermost
switches if necessary.

The get_tag_protocol() function is therefore updated to gain an
additional enum dsa_tag_protocol argument which denotes the current
tagging protocol used by the DSA master we are attached to, else
DSA_TAG_PROTO_NONE for the top of the dsa_switch_tree.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-08 16:01:13 -08:00
Vladimir Oltean
a68578c20a net: dsa: Make deferred_xmit private to sja1105
There are 3 things that are wrong with the DSA deferred xmit mechanism:

1. Its introduction has made the DSA hotpath ever so slightly more
   inefficient for everybody, since DSA_SKB_CB(skb)->deferred_xmit needs
   to be initialized to false for every transmitted frame, in order to
   figure out whether the driver requested deferral or not (a very rare
   occasion, rare even for the only driver that does use this mechanism:
   sja1105). That was necessary to avoid kfree_skb from freeing the skb.

2. Because L2 PTP is a link-local protocol like STP, it requires
   management routes and deferred xmit with this switch. But as opposed
   to STP, the deferred work mechanism needs to schedule the packet
   rather quickly for the TX timstamp to be collected in time and sent
   to user space. But there is no provision for controlling the
   scheduling priority of this deferred xmit workqueue. Too bad this is
   a rather specific requirement for a feature that nobody else uses
   (more below).

3. Perhaps most importantly, it makes the DSA core adhere a bit too
   much to the NXP company-wide policy "Innovate Where It Doesn't
   Matter". The sja1105 is probably the only DSA switch that requires
   some frames sent from the CPU to be routed to the slave port via an
   out-of-band configuration (register write) rather than in-band (DSA
   tag). And there are indeed very good reasons to not want to do that:
   if that out-of-band register is at the other end of a slow bus such
   as SPI, then you limit that Ethernet flow's throughput to effectively
   the throughput of the SPI bus. So hardware vendors should definitely
   not be encouraged to design this way. We do _not_ want more
   widespread use of this mechanism.

Luckily we have a solution for each of the 3 issues:

For 1, we can just remove that variable in the skb->cb and counteract
the effect of kfree_skb with skb_get, much to the same effect. The
advantage, of course, being that anybody who doesn't use deferred xmit
doesn't need to do any extra operation in the hotpath.

For 2, we can create a kernel thread for each port's deferred xmit work.
If the user switch ports are named swp0, swp1, swp2, the kernel threads
will be named swp0_xmit, swp1_xmit, swp2_xmit (there appears to be a 15
character length limit on kernel thread names). With this, the user can
change the scheduling priority with chrt $(pidof swp2_xmit).

For 3, we can actually move the entire implementation to the sja1105
driver.

So this patch deletes the generic implementation from the DSA core and
adds a new one, more adequate to the requirements of PTP TX
timestamping, in sja1105_main.c.

Suggested-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-05 15:13:13 -08:00
Vladimir Oltean
0a51826c6e net: dsa: sja1105: Always send through management routes in slot 0
I finally found out how the 4 management route slots are supposed to
be used, but.. it's not worth it.

The description from the comment I've just deleted in this commit is
still true: when more than 1 management slot is active at the same time,
the switch will match frames incoming [from the CPU port] on the lowest
numbered management slot that matches the frame's DMAC.

My issue was that one was not supposed to statically assign each port a
slot. Yes, there are 4 slots and also 4 non-CPU ports, but that is a
mere coincidence.

Instead, the switch can be used like this: every management frame gets a
slot at the right of the most recently assigned slot:

Send mgmt frame 1 through S0:    S0 x  x  x
Send mgmt frame 2 through S1:    S0 S1 x  x
Send mgmt frame 3 through S2:    S0 S1 S2 x
Send mgmt frame 4 through S3:    S0 S1 S2 S3

The difference compared to the old usage is that the transmission of
frames 1-4 doesn't need to wait until the completion of the management
route. It is safe to use a slot to the right of the most recently used
one, because by protocol nobody will program a slot to your left and
"steal" your route towards the correct egress port.

So there is a potential throughput benefit here.

But mgmt frame 5 has no more free slot to use, so it has to wait until
_all_ of S0, S1, S2, S3 are full, in order to use S0 again.

And that's actually exactly the problem: I was looking for something
that would bring more predictable transmission latency, but this is
exactly the opposite: 3 out of 4 frames would be transmitted quicker,
but the 4th would draw the short straw and have a worse worst-case
latency than before.

Useless.

Things are made even worse by PTP TX timestamping, which is something I
won't go deeply into here. Suffice to say that the fact there is a
driver-level lock on the SPI bus offsets any potential throughput gains
that parallelism might bring.

So there's no going back to the multi-slot scheme, remove the
"mgmt_slot" variable from sja1105_port and the dummy static assignment
made at probe time.

While passing by, also remove the assignment to casc_port altogether.
Don't pretend that we support cascaded setups.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-05 15:13:12 -08:00
David S. Miller
31d518f35e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Simple overlapping changes in bpf land wrt. bpf_helper_defs.h
handling.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-31 13:37:13 -08:00
Vladimir Oltean
19d1f0ed74 net: dsa: sja1105: Empty the RX timestamping queue on PTP settings change
When disabling PTP timestamping, don't reset the switch with the new
static config until all existing PTP frames have been timestamped on the
RX path or dropped. There's nothing we can do with these afterwards.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-30 20:31:40 -08:00
Vladimir Oltean
1e762bd278 net: dsa: sja1105: Use PTP core's dedicated kernel thread for RX timestamping
And move the queue of skb's waiting for RX timestamps into the ptp_data
structure, since it isn't needed if PTP is not compiled.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-30 20:31:40 -08:00
Vladimir Oltean
54fa49ee88 net: dsa: sja1105: Reconcile the meaning of TPID and TPID2 for E/T and P/Q/R/S
For first-generation switches (SJA1105E and SJA1105T):
- TPID means C-Tag (typically 0x8100)
- TPID2 means S-Tag (typically 0x88A8)

While for the second generation switches (SJA1105P, SJA1105Q, SJA1105R,
SJA1105S) it is the other way around:
- TPID means S-Tag (typically 0x88A8)
- TPID2 means C-Tag (typically 0x8100)

In other words, E/T tags untagged traffic with TPID, and P/Q/R/S with
TPID2.

So the patch mentioned below fixed VLAN filtering for P/Q/R/S, but broke
it for E/T.

We strive for a common code path for all switches in the family, so just
lie in the static config packing functions that TPID and TPID2 are at
swapped bit offsets than they actually are, for P/Q/R/S. This will make
both switches understand TPID to be ETH_P_8021Q and TPID2 to be
ETH_P_8021AD. The meaning from the original E/T was chosen over P/Q/R/S
because E/T is actually the one with public documentation available
(UM10944.pdf).

Fixes: f9a1a7646c ("net: dsa: sja1105: Reverse TPID and TPID2")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-30 20:15:02 -08:00
Vladimir Oltean
d00bdc0a88 net: dsa: sja1105: Remove restriction of zero base-time for taprio offload
The check originates from the initial implementation which was not based
on PTP time but on a standalone clock source. In the meantime we can now
program the PTPSCHTM register at runtime with the dynamic base time
(actually with a value that is 200 ns smaller, to avoid writing DELTA=0
in the Schedule Entry Points Parameters Table). And we also have logic
for moving the actual base time in the future of the PHC's current time
base, so the check for zero serves no purpose, since even if the user
will specify zero, that's not what will end up in the static config
table where the limitation is.

Fixes: 86db36a347 ("net: dsa: sja1105: Implement state machine for TAS with PTP clock source")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-30 20:13:11 -08:00
Vladimir Oltean
5a47f588ee net: dsa: sja1105: Really make the PTP command read-write
When activating tc-taprio offload on the switch ports, the TAS state
machine will try to check whether it is running or not, but will find
both the STARTED and STOPPED bits as false in the
sja1105_tas_check_running function. So the function will return -EINVAL
(an abnormal situation) and the kernel will keep printing this from the
TAS FSM workqueue:

[   37.691971] sja1105 spi0.1: An operation returned -22

The reason is that the underlying function that gets called,
sja1105_ptp_commit, does not actually do a SPI_READ, but a SPI_WRITE. So
the command buffer remains initialized with zeroes instead of retrieving
the hardware state. Fix that.

Fixes: 41603d78b3 ("net: dsa: sja1105: Make the PTP command read-write")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-30 20:11:28 -08:00
Vladimir Oltean
9fcf024dd6 net: dsa: sja1105: Take PTP egress timestamp by port, not mgmt slot
The PTP egress timestamp N must be captured from register PTPEGR_TS[n],
where n = 2 * PORT + TSREG. There are 10 PTPEGR_TS registers, 2 per
port. We are only using TSREG=0.

As opposed to the management slots, which are 4 in number
(SJA1105_NUM_PORTS, minus the CPU port). Any management frame (which
includes PTP frames) can be sent to any non-CPU port through any
management slot. When the CPU port is not the last port (#4), there will
be a mismatch between the slot and the port number.

Luckily, the only mainline occurrence with this switch
(arch/arm/boot/dts/ls1021a-tsn.dts) does have the CPU port as #4, so the
issue did not manifest itself thus far.

Fixes: 47ed985e97 ("net: dsa: sja1105: Add logic for TX timestamping")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-30 20:10:20 -08:00
David S. Miller
adf6f8cb3f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in networking bug fixes for merge window.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-25 14:57:26 -08:00
Oleksij Rempel
9bca3a0a92 net: dsa: sja1105: fix sja1105_parse_rgmii_delays()
This function was using configuration of port 0 in devicetree for all ports.
In case CPU port was not 0, the delay settings was ignored. This resulted not
working communication between CPU and the switch.

Fixes: f5b8631c29 ("net: dsa: sja1105: Error out if RGMII delays are requested in DT")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-25 10:56:12 -08:00
Vladimir Oltean
abfb228ae6 net: dsa: sja1105: Simplify reset handling
We don't really need 10k species of reset. Remove everything except cold
reset which is what is actually used. Too bad the hardware designers
couldn't agree to use the same bit field for rev 1 and rev 2, so the
(*reset_cmd) function pointer is there to stay.

However let's simplify the prototype and give it a struct dsa_switch (we
want to avoid forward-declarations of structures, in this case struct
sja1105_private, wherever we can).

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-14 15:11:17 -08:00
Vladimir Oltean
86db36a347 net: dsa: sja1105: Implement state machine for TAS with PTP clock source
Tested using the following bash script and the tc from iproute2-next:

	#!/bin/bash

	set -e -u -o pipefail

	NSEC_PER_SEC="1000000000"

	gatemask() {
		local tc_list="$1"
		local mask=0

		for tc in ${tc_list}; do
			mask=$((${mask} | (1 << ${tc})))
		done

		printf "%02x" ${mask}
	}

	if ! systemctl is-active --quiet ptp4l; then
		echo "Please start the ptp4l service"
		exit
	fi

	now=$(phc_ctl /dev/ptp1 get | gawk '/clock time is/ { print $5; }')
	# Phase-align the base time to the start of the next second.
	sec=$(echo "${now}" | gawk -F. '{ print $1; }')
	base_time="$(((${sec} + 1) * ${NSEC_PER_SEC}))"

	tc qdisc add dev swp5 parent root handle 100 taprio \
		num_tc 8 \
		map 0 1 2 3 5 6 7 \
		queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 \
		base-time ${base_time} \
		sched-entry S $(gatemask 7) 100000 \
		sched-entry S $(gatemask "0 1 2 3 4 5 6") 400000 \
		clockid CLOCK_TAI flags 2

The "state machine" is a workqueue invoked after each manipulation
command on the PTP clock (reset, adjust time, set time, adjust
frequency) which checks over the state of the time-aware scheduler.
So it is not monitored periodically, only in reaction to a PTP command
typically triggered from a userspace daemon (linuxptp). Otherwise there
is no reason for things to go wrong.

Now that the timecounter/cyclecounter has been replaced with hardware
operations on the PTP clock, the TAS Kconfig now depends upon PTP and
the standalone clocksource operating mode has been removed.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-14 14:50:35 -08:00
Vladimir Oltean
41603d78b3 net: dsa: sja1105: Make the PTP command read-write
The PTPSTRTSCH and PTPSTOPSCH bits are actually readable and indicate
whether the time-aware scheduler is running or not. We will be using
that for monitoring the scheduler in the next patch, so refactor the PTP
command API in order to allow that.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-14 14:50:35 -08:00
Vladimir Oltean
2eea1fa82f net: dsa: sja1105: Print the reset reason
Sometimes it can be quite opaque even for me why the driver decided to
reset the switch. So instead of adding dump_stack() calls each time for
debugging, just add a reset reason to sja1105_static_config_reload
calls which gets printed to the console.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-12 19:53:07 -08:00
Vladimir Oltean
af580ae2dc net: dsa: sja1105: Disallow management xmit during switch reset
The purpose here is to avoid ptp4l fail due to this condition:

  timed out while polling for tx timestamp
  increasing tx_timestamp_timeout may correct this issue, but it is likely caused by a driver bug
  port 1: send peer delay request failed

So either reset the switch before the management frame was sent, or
after it was timestamped as well, but not in the middle.

The condition may arise either due to a true timeout (i.e. because
re-uploading the static config takes time), or due to the TX timestamp
actually getting lost due to reset. For the former we can increase
tx_timestamp_timeout in userspace, for the latter we need this patch.

Locking all traffic during switch reset does not make sense at all,
though. Forcing all CPU-originated traffic to potentially block waiting
for a sleepable context to send > 800 bytes over SPI is not a good idea.
Flows that are autonomously forwarded by the switch will get dropped
anyway during switch reset no matter what. So just let all other
CPU-originated traffic be dropped as well.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-11 12:45:31 -08:00
Vladimir Oltean
6cf99c13ea net: dsa: sja1105: Restore PTP time after switch reset
The PTP time of the switch is not preserved when uploading a new static
configuration. Work around this hardware oddity by reading its PTP time
before a static config upload, and restoring it afterwards.

Static config changes are expected to occur at runtime even in scenarios
directly related to PTP, i.e. the Time-Aware Scheduler of the switch is
programmed in this way.

Perhaps the larger implication of this patch is that the PTP .gettimex64
and .settime functions need to be exposed to sja1105_main.c, where the
PTP lock needs to be held during this entire process. So their core
implementation needs to move to some common functions which get exposed
in sja1105_ptp.h.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-11 12:45:30 -08:00
Vladimir Oltean
34d76e9fa8 net: dsa: sja1105: Implement the .gettimex64 system call for PTP
Through the PTP_SYS_OFFSET_EXTENDED ioctl, it is possible for userspace
applications (i.e. phc2sys) to compensate for the delays incurred while
reading the PHC's time.

The task itself of taking the software timestamp is delegated to the SPI
subsystem, through the newly introduced API in struct spi_transfer. The
goal is to cross-timestamp I/O operations on the switch's PTP clock with
values in the local system clock (CLOCK_REALTIME). For that we need to
understand a bit of the hardware internals.

The 'read PTP time' message is a 12 byte structure, first 4 bytes of
which represent the SPI header, and the last 8 bytes represent the
64-bit PTP time. The switch itself starts processing the command
immediately after receiving the last bit of the address, i.e. at the
middle of byte 3 (last byte of header). The PTP time is shadowed to a
buffer register in the switch, and retrieved atomically during the
subsequent SPI frames.

A similar thing goes on for the 'write PTP time' message, although in
that case the switch waits until the 64-bit PTP time becomes fully
available before taking any action. So the byte that needs to be
software-timestamped is byte 11 (last) of the transfer.

The patch creates a common (and local) sja1105_xfer implementation for
the SPI I/O, and offers 3 front-ends:

- sja1105_xfer_u32 and sja1105_xfer_u64: these are capable of optionally
  requesting a PTP timestamp

- sja1105_xfer_buf: this is for large transfers (e.g. the static config
  buffer) and other misc data, and there is no point in giving
  timestamping capabilities to this.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-11 12:45:30 -08:00
Andrew Lunn
0c65b2b90d net: of_get_phy_mode: Change API to solve int/unit warnings
Before this change of_get_phy_mode() returned an enum,
phy_interface_t. On error, -ENODEV etc, is returned. If the result of
the function is stored in a variable of type phy_interface_t, and the
compiler has decided to represent this as an unsigned int, comparision
with -ENODEV etc, is a signed vs unsigned comparision.

Fix this problem by changing the API. Make the function return an
error, or 0 on success, and pass a pointer, of type phy_interface_t,
where the phy mode should be stored.

v2:
Return with *interface set to PHY_INTERFACE_MODE_NA on error.
Add error checks to all users of of_get_phy_mode()
Fixup a few reverse christmas tree errors
Fixup a few slightly malformed reverse christmas trees

v3:
Fix 0-day reported errors.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-04 11:21:25 -08:00
David S. Miller
d31e95585c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The only slightly tricky merge conflict was the netdevsim because the
mutex locking fix overlapped a lot of driver reload reorganization.

The rest were (relatively) trivial in nature.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-02 13:54:56 -07:00
Arnd Bergmann
5d294fc483 net: dsa: sja1105: improve NET_DSA_SJA1105_TAS dependency
An earlier bugfix introduced a dependency on CONFIG_NET_SCH_TAPRIO,
but this missed the case of NET_SCH_TAPRIO=m and NET_DSA_SJA1105=y,
which still causes a link error:

drivers/net/dsa/sja1105/sja1105_tas.o: In function `sja1105_setup_tc_taprio':
sja1105_tas.c:(.text+0x5c): undefined reference to `taprio_offload_free'
sja1105_tas.c:(.text+0x3b4): undefined reference to `taprio_offload_get'
drivers/net/dsa/sja1105/sja1105_tas.o: In function `sja1105_tas_teardown':
sja1105_tas.c:(.text+0x6ec): undefined reference to `taprio_offload_free'

Change the dependency to only allow selecting the TAS code when it
can link against the taprio code.

Fixes: a8d570de0c ("net: dsa: sja1105: Add dependency for NET_DSA_SJA1105_TAS")
Fixes: 317ab5b86c ("net: dsa: sja1105: Configure the Time-Aware Scheduler via tc-taprio offload")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-28 16:33:42 -07:00
Vivien Didelot
7e99e34701 net: dsa: remove dsa_switch_alloc helper
Now that ports are dynamically listed in the fabric, there is no need
to provide a special helper to allocate the dsa_switch structure. This
will give more flexibility to drivers to embed this structure as they
wish in their private structure.

Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-22 12:37:07 -07:00
Vivien Didelot
d5a619bf60 net: dsa: sja1105: register switch before assigning port private data
Like the dsa_switch_tree structures, the dsa_port structures will be
allocated on switch registration.

The SJA1105 driver is the only one accessing the dsa_port structure
after the switch allocation and before the switch registration.
For that reason, move switch registration prior to assigning the priv
member of the dsa_port structures.

Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-22 12:37:07 -07:00
Vivien Didelot
68bb8ea8ad net: dsa: use dsa_to_port helper everywhere
Do not let the drivers access the ds->ports static array directly
while there is a dsa_to_port helper for this purpose.

At the same time, un-const this helper since the SJA1105 driver
assigns the priv member of the returned dsa_port structure.

Signed-off-by: Vivien Didelot <vivien.didelot@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-10-22 12:37:06 -07:00
David S. Miller
2f184393e0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Several cases of overlapping changes which were for the most
part trivially resolvable.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-20 10:43:00 -07:00
Vladimir Oltean
2fb079a28a net: dsa: sja1105: Switch to hardware operations for PTP
Adjusting the hardware clock (PTPCLKVAL, PTPCLKADD, PTPCLKRATE) is a
requirement for the auxiliary PTP functionality of the switch
(TTEthernet, PPS input, PPS output).

Therefore we need to switch to using these registers to keep a
synchronized time in hardware, instead of the timecounter/cyclecounter
implementation, which is reliant on the free-running PTPTSCLK.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-18 12:55:30 -04:00
Nishad Kamdar
b790b5549b net: dsa: sja1105: Use the correct style for SPDX License Identifier
This patch corrects the SPDX License Identifier style
in header files related to Distributed Switch Architecture
drivers for NXP SJA1105 series Ethernet switch support.
It uses an expilict block comment for the SPDX License
Identifier.

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-15 20:16:26 -07:00
Vladimir Oltean
08839c06e9 net: dsa: sja1105: Switch to scatter/gather API for SPI
This reworks the SPI transfer implementation to make use of more of the
SPI core features. The main benefit is to avoid the memcpy in
sja1105_xfer_buf().

The memcpy was only needed because the function was transferring a
single buffer at a time. So it needed to copy the caller-provided buffer
at buf + 4, to store the SPI message header in the "headroom" area.

But the SPI core supports scatter-gather messages, comprised of multiple
transfers. We can actually use those to break apart every SPI message
into 2 transfers: one for the header and one for the actual payload.

To keep the behavior the same regarding the chip select signal, it is
necessary to tell the SPI core to de-assert the chip select after each
chunk. This was not needed before, because each spi_message contained
only 1 single transfer.

The meaning of the per-transfer cs_change=1 is:

- If the transfer is the last one of the message, keep CS asserted
- Otherwise, deassert CS

We need to deassert CS in the "otherwise" case, which was implicit
before.

Avoiding the memcpy creates yet another opportunity. The device can't
process more than 256 bytes of SPI payload at a time, so the
sja1105_xfer_long_buf() function used to exist, to split the larger
caller buffer into chunks.

But these chunks couldn't be used as scatter/gather buffers for
spi_message until now, because of that memcpy (we would have needed more
memory for each chunk). So we can now remove the sja1105_xfer_long_buf()
function and have a single implementation for long and short buffers.

Another benefit is lower usage of stack memory. Previously we had to
store 2 SPI buffers for each chunk. Due to the elimination of the
memcpy, we can now send pointers to the actual chunks from the
caller-supplied buffer to the SPI core.

Since the patch merges two functions into a rewritten implementation,
the function prototype was also changed, mainly for cosmetic consistency
with the structures used within it.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-15 13:16:57 -04:00
Vladimir Oltean
8a559400da net: dsa: sja1105: Move sja1105_spi_transfer into sja1105_xfer
This is a cosmetic patch that reduces some boilerplate in the SPI
interaction of the driver.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-15 13:16:56 -04:00
Vladimir Oltean
664277781c net: dsa: sja1105: Change the PTP command access pattern
The PTP command register contains enable bits for:
- Putting the 64-bit PTPCLKVAL register in add/subtract or write mode
- Taking timestamps off of the corrected vs free-running clock
- Starting/stopping the TTEthernet scheduling
- Starting/stopping PPS output
- Resetting the switch

When a command needs to be issued (e.g. "change the PTPCLKVAL from write
mode to add/subtract mode"), one cannot simply write to the command
register setting the PTPCLKADD bit to 1, because that would zeroize the
other settings. One also cannot do a read-modify-write (that would be
too easy for this hardware) because not all bits of the command register
are readable over SPI.

So this leaves us with the only option of keeping the value of the PTP
command register in the driver, and operating on that.

Actually there are 2 types of PTP operations now:
- Operations that modify the cached PTP command. These operate on
  ptp_data->cmd as a pointer.
- Operations that apply all previously cached PTP settings, but don't
  otherwise cache what they did themselves. The sja1105_ptp_reset
  function is such an example. It copies the ptp_data->cmd on stack
  before modifying and writing it to SPI.

This practically means that struct sja1105_ptp_cmd is no longer an
implementation detail, since it needs to be stored in full into struct
sja1105_ptp_data, and hence in struct sja1105_private. So the (*ptp_cmd)
function prototype can change and take struct sja1105_ptp_cmd as second
argument now.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-14 16:45:40 -07:00
Vladimir Oltean
a9d6ed7a8b net: dsa: sja1105: Move PTP data to its own private structure
This is a non-functional change with 2 goals (both for the case when
CONFIG_NET_DSA_SJA1105_PTP is not enabled):

- Reduce the size of the sja1105_private structure.
- Make the PTP code more self-contained.

Leaving priv->ptp_data.lock to be initialized in sja1105_main.c is not a
leftover: it will be used in a future patch "net: dsa: sja1105: Restore
PTP time after switch reset".

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-14 16:45:40 -07:00
Vladimir Oltean
61c7712627 net: dsa: sja1105: Make all public PTP functions take dsa_switch as argument
The new rule (as already started for sja1105_tas.h) is for functions of
optional driver components (ones which may be disabled via Kconfig - PTP
and TAS) to take struct dsa_switch *ds instead of struct sja1105_private
*priv as first argument.

This is so that forward-declarations of struct sja1105_private can be
avoided.

So make sja1105_ptp.h the second user of this rule.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-14 16:45:40 -07:00
Vladimir Oltean
5b3ae43ab1 net: dsa: sja1105: Get rid of global declaration of struct ptp_clock_info
We need priv->ptp_caps to hold a structure and not just a pointer,
because we use container_of in the various PTP callbacks.

Therefore, the sja1105_ptp_caps structure declared in the global memory
of the driver serves no further purpose after copying it into
priv->ptp_caps.

So just populate priv->ptp_caps with the needed operations and remove
sja1105_ptp_caps.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-14 16:45:40 -07:00
David S. Miller
6f4c930e02 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-05 13:37:23 -07:00
zhengbin
26e0105550 net: dsa: sja1105: Make function sja1105_xfer_long_buf static
Fix sparse warnings:

drivers/net/dsa/sja1105/sja1105_spi.c:159:5: warning: symbol 'sja1105_xfer_long_buf' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-04 17:25:04 -07:00
Vladimir Oltean
511e6ca047 net: dsa: sja1105: Add support for port mirroring
Amazingly, of all features, this does not require a switch reset.

Tested with:

tc qdisc add dev swp2 clsact
tc filter add dev swp2 ingress matchall skip_sw \
	action mirred egress mirror dev swp3
tc filter show dev swp2 ingress
tc filter del dev swp2 ingress pref 49152

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-04 14:43:25 -07:00
Vladimir Oltean
1bd4487038 net: dsa: sja1105: Rename sja1105_spi_send_packed_buf to sja1105_xfer_buf
The most commonly called function in the driver is long due for a
rename. The "packed" word is redundant (it doesn't make sense to
transfer an unpacked structure, since that is in CPU endianness yadda
yadda), and the "spi" word is also redundant since argument 2 of the
function is SPI_READ or SPI_WRITE.

As for the sja1105_spi_send_long_packed_buf function, it is only being
used from sja1105_spi.c, so remove its global prototype.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-02 12:25:11 -04:00
Vladimir Oltean
dff79620c3 net: dsa: sja1105: Replace sja1105_spi_send_int with sja1105_xfer_{u32, u64}
Having a function that takes a variable number of unpacked bytes which
it generically calls an "int" is confusing and makes auditing patches
next to impossible.

We only use spi_send_int with the int sizes of 32 and 64 bits. So just
make the spi_send_int function less generic and replace it with the
appropriate two explicit functions, which can now type-check the int
pointer type.

Note that there is still a small weirdness in the u32 function, which
has to convert it to a u64 temporary. This is because of how the packing
API works at the moment, but the weirdness is at least hidden from
callers of sja1105_xfer_u32 now.

Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-02 12:25:11 -04:00
Vladimir Oltean
09c1b41255 net: dsa: sja1105: Don't use "inline" function declarations in C files
Let the compiler decide.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-02 12:25:11 -04:00
Vladimir Oltean
3e8db7e560 net: dsa: sja1105: Fix sleeping while atomic in .port_hwtstamp_set
Currently this stack trace can be seen with CONFIG_DEBUG_ATOMIC_SLEEP=y:

[   41.568348] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:909
[   41.576757] in_atomic(): 1, irqs_disabled(): 0, pid: 208, name: ptp4l
[   41.583212] INFO: lockdep is turned off.
[   41.587123] CPU: 1 PID: 208 Comm: ptp4l Not tainted 5.3.0-rc6-01445-ge950f2d4bc7f-dirty #1827
[   41.599873] [<c0313d7c>] (unwind_backtrace) from [<c030e13c>] (show_stack+0x10/0x14)
[   41.607584] [<c030e13c>] (show_stack) from [<c1212d50>] (dump_stack+0xd4/0x100)
[   41.614863] [<c1212d50>] (dump_stack) from [<c037dfc8>] (___might_sleep+0x1c8/0x2b4)
[   41.622574] [<c037dfc8>] (___might_sleep) from [<c122ea90>] (__mutex_lock+0x48/0xab8)
[   41.630368] [<c122ea90>] (__mutex_lock) from [<c122f51c>] (mutex_lock_nested+0x1c/0x24)
[   41.638340] [<c122f51c>] (mutex_lock_nested) from [<c0c6fe08>] (sja1105_static_config_reload+0x30/0x27c)
[   41.647779] [<c0c6fe08>] (sja1105_static_config_reload) from [<c0c7015c>] (sja1105_hwtstamp_set+0x108/0x1cc)
[   41.657562] [<c0c7015c>] (sja1105_hwtstamp_set) from [<c0feb650>] (dev_ifsioc+0x18c/0x330)
[   41.665788] [<c0feb650>] (dev_ifsioc) from [<c0febbd8>] (dev_ioctl+0x320/0x6e8)
[   41.673064] [<c0febbd8>] (dev_ioctl) from [<c0f8b1f4>] (sock_ioctl+0x334/0x5e8)
[   41.680340] [<c0f8b1f4>] (sock_ioctl) from [<c05404a8>] (do_vfs_ioctl+0xb0/0xa10)
[   41.687789] [<c05404a8>] (do_vfs_ioctl) from [<c0540e3c>] (ksys_ioctl+0x34/0x58)
[   41.695151] [<c0540e3c>] (ksys_ioctl) from [<c0301000>] (ret_fast_syscall+0x0/0x28)
[   41.702768] Exception stack(0xe8495fa8 to 0xe8495ff0)
[   41.707796] 5fa0:                   beff4a8c 00000001 00000011 000089b0 beff4a8c beff4a80
[   41.715933] 5fc0: beff4a8c 00000001 0000000c 00000036 b6fa98c8 004e19c1 00000001 00000000
[   41.724069] 5fe0: 004dcedc beff4a6c 004c0738 b6e7af4c
[   41.729860] BUG: scheduling while atomic: ptp4l/208/0x00000002
[   41.735682] INFO: lockdep is turned off.

Enabling RX timestamping will logically disturb the fastpath (processing
of meta frames). Replace bool hwts_rx_en with a bit that is checked
atomically from the fastpath and temporarily unset from the sleepable
context during a change of the RX timestamping process (a destructive
operation anyways, requires switch reset).
If found unset, the fastpath (net/dsa/tag_sja1105.c) will just drop any
received meta frame and not take the meta_lock at all.

Fixes: a602afd200 ("net: dsa: sja1105: Expose PTP timestamping ioctls to userspace")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-02 12:19:53 -04:00
Vladimir Oltean
d6530e5ad4 net: dsa: sja1105: Initialize the meta_lock
Otherwise, with CONFIG_DEBUG_SPINLOCK=y, this stack trace gets printed
when enabling RX timestamping and receiving a PTP frame:

[  318.537078] INFO: trying to register non-static key.
[  318.542040] the code is fine but needs lockdep annotation.
[  318.547500] turning off the locking correctness validator.
[  318.552972] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-13257-g0825b0669811-dirty #1962
[  318.561283] Hardware name: Freescale LS1021A
[  318.565566] [<c03144bc>] (unwind_backtrace) from [<c030e164>] (show_stack+0x10/0x14)
[  318.573289] [<c030e164>] (show_stack) from [<c11b9f50>] (dump_stack+0xd4/0x100)
[  318.580579] [<c11b9f50>] (dump_stack) from [<c03b9b40>] (register_lock_class+0x728/0x734)
[  318.588731] [<c03b9b40>] (register_lock_class) from [<c03b60c4>] (__lock_acquire+0x78/0x25cc)
[  318.597227] [<c03b60c4>] (__lock_acquire) from [<c03b8ef8>] (lock_acquire+0xd8/0x234)
[  318.605033] [<c03b8ef8>] (lock_acquire) from [<c11db934>] (_raw_spin_lock+0x44/0x54)
[  318.612755] [<c11db934>] (_raw_spin_lock) from [<c1164370>] (sja1105_rcv+0x1f8/0x4e8)
[  318.620561] [<c1164370>] (sja1105_rcv) from [<c115d7cc>] (dsa_switch_rcv+0x80/0x204)
[  318.628283] [<c115d7cc>] (dsa_switch_rcv) from [<c0f58c80>] (__netif_receive_skb_one_core+0x50/0x6c)
[  318.637386] [<c0f58c80>] (__netif_receive_skb_one_core) from [<c0f58f04>] (netif_receive_skb_internal+0xac/0x264)
[  318.647611] [<c0f58f04>] (netif_receive_skb_internal) from [<c0f59e98>] (napi_gro_receive+0x1d8/0x338)
[  318.656887] [<c0f59e98>] (napi_gro_receive) from [<c0c298a4>] (gfar_clean_rx_ring+0x328/0x724)
[  318.665472] [<c0c298a4>] (gfar_clean_rx_ring) from [<c0c29e60>] (gfar_poll_rx_sq+0x34/0x94)
[  318.673795] [<c0c29e60>] (gfar_poll_rx_sq) from [<c0f5b40c>] (net_rx_action+0x128/0x4f8)
[  318.681860] [<c0f5b40c>] (net_rx_action) from [<c03022f0>] (__do_softirq+0x148/0x5ac)
[  318.689666] [<c03022f0>] (__do_softirq) from [<c0355af4>] (irq_exit+0x160/0x170)
[  318.697040] [<c0355af4>] (irq_exit) from [<c03c6818>] (__handle_domain_irq+0x60/0xb4)
[  318.704847] [<c03c6818>] (__handle_domain_irq) from [<c07e9440>] (gic_handle_irq+0x58/0x9c)
[  318.713172] [<c07e9440>] (gic_handle_irq) from [<c0301a70>] (__irq_svc+0x70/0x98)
[  318.720622] Exception stack(0xc2001f18 to 0xc2001f60)
[  318.725656] 1f00:                                                       00000001 00000006
[  318.733805] 1f20: 00000000 c20165c0 ffffe000 c2010cac c2010cf4 00000001 00000000 c2010c88
[  318.741955] 1f40: c1f7a5a8 00000000 00000000 c2001f68 c03ba140 c030a288 200e0013 ffffffff
[  318.750110] [<c0301a70>] (__irq_svc) from [<c030a288>] (arch_cpu_idle+0x24/0x3c)
[  318.757486] [<c030a288>] (arch_cpu_idle) from [<c038a480>] (do_idle+0x1b8/0x2a4)
[  318.764859] [<c038a480>] (do_idle) from [<c038a94c>] (cpu_startup_entry+0x18/0x1c)
[  318.772407] [<c038a94c>] (cpu_startup_entry) from [<c1e00f10>] (start_kernel+0x4cc/0x4fc)

Fixes: 844d7edc6a ("net: dsa: sja1105: Add a global sja1105_tagger_data structure")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-02 12:19:53 -04:00
Navid Emamdoost
68501df92d net: dsa: sja1105: Prevent leaking memory
In sja1105_static_config_upload, in two cases memory is leaked: when
static_config_buf_prepare_for_upload fails and when sja1105_inhibit_tx
fails. In both cases config_buf should be released.

Fixes: 8aa9ebccae ("net: dsa: Introduce driver for NXP SJA1105 5-port L2 switch")
Fixes: 1a4c69406c ("net: dsa: sja1105: Prevent PHY jabbering during switch reset")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-30 17:24:43 -07:00
Vladimir Oltean
b6f2494d31 net: dsa: sja1105: Ensure PTP time for rxtstamp reconstruction is not in the past
Sometimes the PTP synchronization on the switch 'jumps':

  ptp4l[11241.155]: rms    8 max   16 freq -21732 +/-  11 delay   742 +/-   0
  ptp4l[11243.157]: rms    7 max   17 freq -21731 +/-  10 delay   744 +/-   0
  ptp4l[11245.160]: rms 33592410 max 134217731 freq +192422 +/- 8530253 delay   743 +/-   0
  ptp4l[11247.163]: rms 811631 max 964131 freq +10326 +/- 557785 delay   743 +/-   0
  ptp4l[11249.166]: rms 261936 max 533876 freq -304323 +/- 126371 delay   744 +/-   0
  ptp4l[11251.169]: rms 48700 max 57740 freq -20218 +/- 30532 delay   744 +/-   0
  ptp4l[11253.171]: rms 14570 max 30163 freq  -5568 +/- 7563 delay   742 +/-   0
  ptp4l[11255.174]: rms 2914 max 3440 freq -22001 +/- 1667 delay   744 +/-   1
  ptp4l[11257.177]: rms  811 max 1710 freq -22653 +/- 451 delay   744 +/-   1
  ptp4l[11259.180]: rms  177 max  218 freq -21695 +/-  89 delay   741 +/-   0
  ptp4l[11261.182]: rms   45 max   92 freq -21677 +/-  32 delay   742 +/-   0
  ptp4l[11263.186]: rms   14 max   32 freq -21733 +/-  11 delay   742 +/-   0
  ptp4l[11265.188]: rms    9 max   14 freq -21725 +/-  12 delay   742 +/-   0
  ptp4l[11267.191]: rms    9 max   16 freq -21727 +/-  13 delay   742 +/-   0
  ptp4l[11269.194]: rms    6 max   15 freq -21726 +/-   9 delay   743 +/-   0
  ptp4l[11271.197]: rms    8 max   15 freq -21728 +/-  11 delay   743 +/-   0
  ptp4l[11273.200]: rms    6 max   12 freq -21727 +/-   8 delay   743 +/-   0
  ptp4l[11275.202]: rms    9 max   17 freq -21720 +/-  11 delay   742 +/-   0
  ptp4l[11277.205]: rms    9 max   18 freq -21725 +/-  12 delay   742 +/-   0

Background: the switch only offers partial RX timestamps (24 bits) and
it is up to the driver to read the PTP clock to fill those timestamps up
to 64 bits. But the PTP clock readout needs to happen quickly enough (in
0.135 seconds, in fact), otherwise the PTP clock will wrap around 24
bits, condition which cannot be detected.

Looking at the 'max 134217731' value on output line 3, one can see that
in hex it is 0x8000003. Because the PTP clock resolution is 8 ns,
that means 0x1000000 in ticks, which is exactly 2^24. So indeed this is
a PTP clock wraparound, but the reason might be surprising.

What is going on is that sja1105_tstamp_reconstruct(priv, now, ts)
expects a "now" time that is later than the "ts" was snapshotted at.
This, of course, is obvious: we read the PTP time _after_ the partial RX
timestamp was received. However, the workqueue is processing frames from
a skb queue and reuses the same PTP time, read once at the beginning.
Normally the skb queue only contains one frame and all goes well. But
when the skb queue contains two frames, the second frame that gets
dequeued might have been partially timestamped by the RX MAC _after_ we
had read our PTP time initially.

The code was originally like that due to concerns that SPI access for
PTP time readout is a slow process, and we are time-constrained anyway
(aka: premature optimization). But some timing analysis reveals that the
time spent until the RX timestamp is completely reconstructed is 1 order
of magnitude lower than the 0.135 s deadline even under worst-case
conditions. So we can afford to read the PTP time for each frame in the
RX timestamping queue, which of course ensures that the full PTP time is
in the partial timestamp's future.

Fixes: f3097be21b ("net: dsa: sja1105: Add a state machine for RX timestamping")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-30 17:20:50 -07:00
Mao Wenan
a8d570de0c net: dsa: sja1105: Add dependency for NET_DSA_SJA1105_TAS
If CONFIG_NET_DSA_SJA1105_TAS=y and CONFIG_NET_SCH_TAPRIO=n,
below error can be found:
drivers/net/dsa/sja1105/sja1105_tas.o: In function `sja1105_setup_tc_taprio':
sja1105_tas.c:(.text+0x318): undefined reference to `taprio_offload_free'
sja1105_tas.c:(.text+0x590): undefined reference to `taprio_offload_get'
drivers/net/dsa/sja1105/sja1105_tas.o: In function `sja1105_tas_teardown':
sja1105_tas.c:(.text+0x610): undefined reference to `taprio_offload_free'
make: *** [vmlinux] Error 1

sja1105_tas needs tc-taprio, so this patch add the dependency for it.

Fixes: 317ab5b86c ("net: dsa: sja1105: Configure the Time-Aware Scheduler via tc-taprio offload")
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-09-21 19:41:19 -07:00
Vladimir Oltean
317ab5b86c net: dsa: sja1105: Configure the Time-Aware Scheduler via tc-taprio offload
This qdisc offload is the closest thing to what the SJA1105 supports in
hardware for time-based egress shaping. The switch core really is built
around SAE AS6802/TTEthernet (a TTTech standard) but can be made to
operate similarly to IEEE 802.1Qbv with some constraints:

- The gate control list is a global list for all ports. There are 8
  execution threads that iterate through this global list in parallel.
  I don't know why 8, there are only 4 front-panel ports.

- Care must be taken by the user to make sure that two execution threads
  never get to execute a GCL entry simultaneously. I created a O(n^4)
  checker for this hardware limitation, prior to accepting a taprio
  offload configuration as valid.

- The spec says that if a GCL entry's interval is shorter than the frame
  length, you shouldn't send it (and end up in head-of-line blocking).
  Well, this switch does anyway.

- The switch has no concept of ADMIN and OPER configurations. Because
  it's so simple, the TAS settings are loaded through the static config
  tables interface, so there isn't even place for any discussion about
  'graceful switchover between ADMIN and OPER'. You just reset the
  switch and upload a new OPER config.

- The switch accepts multiple time sources for the gate events. Right
  now I am using the standalone clock source as opposed to PTP. So the
  base time parameter doesn't really do much. Support for the PTP clock
  source will be added in a future series.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-16 21:32:58 +02:00
Vladimir Oltean
5f06c63bd3 net: dsa: sja1105: Advertise the 8 TX queues
This is a preparation patch for the tc-taprio offload (and potentially
for other future offloads such as tc-mqprio).

Instead of looking directly at skb->priority during xmit, let's get the
netdev queue and the queue-to-traffic-class mapping, and put the
resulting traffic class into the dsa_8021q PCP field. The switch is
configured with a 1-to-1 PCP-to-ingress-queue-to-egress-queue mapping
(see vlan_pmap in sja1105_main.c), so the effect is that we can inject
into a front-panel's egress traffic class through VLAN tagging from
Linux, completely transparently.

Unfortunately the switch doesn't look at the VLAN PCP in the case of
management traffic to/from the CPU (link-local frames at
01-80-C2-xx-xx-xx or 01-1B-19-xx-xx-xx) so we can't alter the
transmission queue of this type of traffic on a frame-by-frame basis. It
is only selected through the "hostprio" setting which ATM is harcoded in
the driver to 7.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-16 21:32:57 +02:00
Vladimir Oltean
7f1e4ba814 net: dsa: sja1105: Add static config tables for scheduling
In order to support tc-taprio offload, the TTEthernet egress scheduling
core registers must be made visible through the static interface.

Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-16 21:32:57 +02:00